Permanent-magnet armature for polarized electromagnetic systems, in particular for polarized relays



Dec. 30, 1958 H. BERG ET AL 2,866,927

PERMANENT-MAGNET ARMATURE FOR POLARIZED ELECTROMAGNETIC SYSTEMS, IN PARTICULAR FOR POLARIZED RELAYS Filed Sept. '7. 1955 Fi .1 Fi .2 Fig.2a

Fig.3 Fi .1.

I El Unite tates Patent PERMANENT-MAGNET ARMATURE FOR POLAR- IZED ELECTROMAGNETIC SYSTEMS, IN PAR- TICULAR FOR POLARIZED RELAYS Herbert Berg and Josef Fischer, Munich, Herbert Krautwald, Munich-Solln, and Alois Ruhland, Munich, Germany, assiguors to Siemens & Halske, Aktiengesellschaft, Munich and Berlin, Germany, Germany The invention relates generally to armatures of the permanent-magnet type for use in polarized electromagnetic systems and the like, and in particular for armatures utilized in polarized relays.

n polarized electromagnetic systems the mounting of the permanent magnet to be provided in the armature offers difficulties insofar as the material of high-grade magnets is extraordinarily hard and -very brittle so that it can be processed only with great difficulty and possesses relatively poor characteristics as to tensile strength, etc., whereby it does not satisfactorily withstand the pulling and bending stresses to which it may be subjected. The invention relates to a method of mounting that requires no special processing of the permanent-magnet body whatsoever and introduces merely a compression stress on the latter. In the event that the permanent-magnet body carries at either end pole piece plates interworking with corresponding pole pieces of the stator, this has been achieved in accordance with the invention by means whereby the permanent-magnet body may be loosely placed between the plates and firmly clamped together with a clamping strap gripping around the plates. This type of assembly can be carried out very simply and used to advantage in particular also for very small polarized armatures. The clamping strap itself is supported, hinged in a suitable manner with pivots or ribbons on the relay frame or casing. I

In the drawings, wherein the referred characteristics indicate like or corresponding parts;

Fig. l is a schematic or semi-diagrammatic layout of a polarized relay illustrating the magnetic relationships;

Fig. 2 is a side elevational view of an armature structure embodying the present invention;

Fig. 2a is a sectional view taken approximately through the center of the clamping structure;

Fig. 3 is an elevational view similar to Fig. 2 of another embodiment of the invention;

Fig. 3a is a sectional view similar to Fig. 2a of the structure illustrated in Fig. 3;

Fig. 4 is a side elevational view of still another embodiment of the invention; and v Fig. 4a is a partial transverse sectional view, similar to Figs. 2a and 3a of the embodiment illustrated in Fig. 4-.

The clamping strap may be designed in different ways, three embodiments thereof being shown schematically in Figs. 2, 3 and 4 of the drawing.

Fig. l of the drawing shows first the schematical layout of the polarized relay. The armature is essentially shaped as a double-T and consists of the cube-shaped or parallelepiped-shaped permanent-magnet body a and the pole-piece plates a and a bearing on it at either side. Between these plates project from above and below the pole pieces b and b of the stator that are connected to the core of the relay coil d by the yokes c and The armature is permanently magnetized in the direction of the arrows shown in the drawing and produces the cona corporation of Patented'Dec. 3Q, 1958 tively. of this excitation to cause a deflection of the arma-:

ture in the. one or other direction. The armature .may actuate suitable means, as for example, a set of contact springs not shown in the drawing.

In the embodiment illustrated in Figs. 2 and 2a, the clamping strap retaining the permanent-magnet body a and the pole piece plates a and a together comprises a U-shaped bow e and a spring clip 1 slidable over the ends of the bow legs and having tong-shaped points f which may enter corresponding openings 2 of the bow legs. The plates a and a may have recesses corresponding to the width of the how 2 over which the bow is slipped. The bow may also be provided with pivots z or other suitable means for supporting the armature.

In the embodiment illustrated in Figs. 3 and 3a the bow E is designed as a resilient strap. The crossbar is bulged out and bears against the left-hand resilient plate a The parts a, a and a may be slid loosely one behind the other into the bow; following which the crossbar may be sprung sufiiciently to permit lugs a provided at the ends of the bow leg to fall behind the edges of the outer plate a as clearly illustrated in Fig. 3a. The bow E carries again in a suitable manner the pivots z, or other means supporting the armature.

The embodiment illustrated in Figs. 4 and 4a is generally similar to that illustrated in Figs. 2 and 2a, but the arrangement in accordance with Fig. 4 uses instead of the resilient clamping strap 1 of Fig. 2, a clamping plate p slid through corresponding openings of the legs of the bow e and containing two grub screws st screwed against the pole piece sheet a located at the right and thus bracing the armature parts a, a and a firmly against each other.

It will be noted from the above description that the present invention enables the assembly of the loose magnet and pole pieces by a simple structure which introduces compression forces on the components to firmly retain the latter in operative position and eliminating any necessity of placing the magnet structure or associated elements under bending or other stresses to which the magnet, due to the characteristics of the material comprising the same, is not suited.

We claim:

1. In a permanent-magnet armature for polarized relays, the combination of a pair of spaced pole pieces, a permanent-magnet body interposed between the pole pieces, a connecting structure having spaced members bridging the pole pieces at opposite sides of the magnet body, elements associated with the spaced members at the respective ends thereof and engageable with adjacent pole pieces, at least one of said elements being movable in a direction toward or away from the adjacent pole piece and cooperable with an element adjacent the opposite pole piece to exert compression forces on the armature assembly to retain the same in fixed assembled relation.

2. A permanent-magnet armature as defined in claim 1, wherein said connecting structure is provided with means for operatively supporting the armature.

3. A permanent-magnet armature as defined in claim 1, wherein the spaced members and an element adjacent one of said pole pieces are formed as an integral generally U-shaped how.

4. A permanent-magnet armature as defined in claim 1, wherein the spaced members and an element adjacent one of said pole pieces are formed as an integral generally U-shaped bow, a portion of said connecting structure adjacent one of said pole pieces being in the form of a resilient spring operative to apply compression forces to the adjacent pole piece.

7. A permanent-magnet armature as definedin claim6', I

wherein said resilient-element 'is a; spring of substantially U-shapehaving inwardly turned" ends adapted to enter into corresponding openings in the bow legs to operatively connect the same, said-spring havinga bow therein bearing in a resilient manneragainst' the outer face of the adjacent p'ole piece.

8. A permanent-magnet. armature as defined in claim 4, wherein said U-shaped-bow is made of resilient'materi'alwith: the "intermediate-portion thereof being bowed inwardlyand vbearingin a resilient manner against the adjacent pole piece, the freeends 'of the bow legs -having opposed inwardly directed deten't lugs thereon-engageable' with the adjacent pole piece to retain the -latter-in en gagement with the bow.

4 9. A permanent-magnet armature as defined in claim 3,

wherein the free ends of said how legsare each provided with an opening therein in. which is positioned a respective end of a crossbar extending across the exterior face of the adjacent pole piece, and a grub screw threaded into said crossbar engageable with the adjacent pole piece for applying compression forces thereto.

References Cited in the file of this patent UNITED STATES PATENTS 1,256,426 Baltzley Feb. 12, 1918 1,847,012 Lavet Feb. 23, 1932 2,435,487 Adler Feb. 3, 1948 2,517,214 Kent Aug. 1,1950 2,716,795 Harker Sept. 6, 1955 FOREIGN PATENTS 479,106 Canada Dec. 4, 1951 923,563 Germany Feb. 17, 1955 1,103,207 France ...-a May 18, 1955 

